Done mine couple yrs ago best thing ever,,05 GMC 2500 HD ,,,6.0 GAS 4L80 TRANS 4X4. Fuel mileage up don't know exactly never checked,,,but definitely worth it,, up 1 or 2 sizes in tires, HD has 4 10 gears,, don't go over board!,,also my tune guy put a 15% power enrichment at 60% throttle,,I couldn't be happier

I just installed my fans, but the second fan doesn't come on. I have an 02 escalade but I didn't realize the aftermarket wire harness I got was for the 03-04 models. Wich like you said they are supposed to be wired a little different. (IE, green wire to blue connector pin 42 and blue wire to green conn pin 33 on the 03-04 trucks. But 99-02 the blue wire is supposed to go the the AC signal wire) I did green wire to blue connector 42 and blue wire to red connector 33 and it doesn't do anything. Do you think if I lower the AC pressure like you suggested, it would work. My tuner has the AC pressure set to something like on at 500 and off at like 425 if I'm not mistaken.

@Mattvardaman

Жыл бұрын

My ac pressure for fan stage 1 (both fans low) is 220 psi and 170, and fan 2 is 280 and 230. The 2nd stage fans won’t come on unless the high pressure switch(ac recirc) is triggered, which means you would have to be idling in summer traffic to need the high speed. On low speed my ac is ice cold, but not using it much here lately. You can use the ac clutch wire to force both fans on, but it’s a 12v +, and the fan triggers are both pcm ground switched. So you would need one more relay to take that + to a -.

@castleclubclipz

Жыл бұрын

If your harness is for 03-04, you got the wrong harness, electric fans didn’t come these trucks until 2005. Also you need to activate the pins in the ECU for it to work properly.

I do not have AC anymore in my truck and did this same swap...it worked great for a little while after I did all the tuning in hp tuners for the e-fans, but now my fans come on right on startup even though they used to trigger in at the temperature setpoint that i programmed. I also have it programmed for the fans to run for 30 seconds after shut down if the truck is above 190 degrees and that is still working like normal. Any thoughts on what I should try to do?

@Mattvardaman

Жыл бұрын

So your using the factory 3 relay controls? Pinned to blue 42, and red 33? What year truck? Are they on low speed on startup or high?

@jefffleming1743

Жыл бұрын

@Matt Vardaman yes factory set up and same pin on ecm and it's an 2002 silverado when I done it last week it worked great but now freezing up the compressor is just staying on not recycling

@jefffleming1743

Жыл бұрын

Low speed

@jefffleming1743

Жыл бұрын

Yes low speed until I reach a certain temp my compressor just isn't recirculating I swapped back over to the high pressure relay and the compressor started recirculating for a min but then it just stayed on

So I’m doing the same swap on my 02 Silverado 1500 4wd ecsb. And I see that you said to remove the ac recirc from 33pin on the red plug. Will it still go into recirc mode? Do you move the ac recirc pin to another pin? I’m using an oem harness as well.

@Mattvardaman

29 күн бұрын

Yes it will still go into recirculation mode when you push the button on ac controls. These trucks have a feature that automatically goes into recirc at idle, and that no longer works when you remove that pin. You have to do this to use the pin for the fans. Does that make sense?

@LSMykie

29 күн бұрын

@@Mattvardaman very much so. I appreciate it lol I left everything tore apart since yesterday til I can get an understanding of it completely. I also changed it in my tune as u did. If I stick the recirc pin in an unused slot will it effect anything else?

@Mattvardaman

29 күн бұрын

@@LSMykie I wouldn’t pin it in an empty slot because I’m not sure what would happen. Probably nothing at all, but I just left unpinned with no adverse effects since the pcm is now using that pin to control the high speed fans.

@LSMykie

29 күн бұрын

@@Mattvardaman gotcha. Thanks again. I’m building my 4l60e at the moment so it’ll be a sec before I can test everything out.

@Mattvardaman

28 күн бұрын

@@LSMykie I had mine rebuilt in march and it broke something catastrophic a 1,000 miles later. My truck is a turbo 5.3 now. The original 4l60e lasted 30,000 miles with the GT45 turbo, but the rebuild broke under light normal driving, searching for a 4l80e or better trans now. Good luck on yours!

I done the fan swap but my ac is freezing up now any fix for that

@Mattvardaman

Жыл бұрын

There are many reasons for ac to freeze up, usually the refrigerant level is a little low, stopped up drain line, or extremely clogged cabin air filter. If it’s only started freezing up since the fan swap, my guess would be the fans are on high when they should be on low. Which wiring harness did you use and which year model is the truck? There are key wiring differences.

@jefffleming1743

Жыл бұрын

I have an 2002 silverado everything is good it just freezes up but I noticed if I turn the air up high it doesn't freeze as bad and my compressor isn't recirculating